Osama bin Laden was protected by elements of Pakistan's security apparatus in
return for millions dollars of Saudi cash, according to a controversial new
account of the operation to kill the world's most wanted man.

US Special Forces attacked the compound where Osama bin Laden lived in MayPhoto: AP/Anjum Naveed

Raelynn Hillhouse, an American security analyst, claimed that bin Laden's whereabouts were finally revealed when a Pakistani intelligence officer came forward to claim the longstanding $25m bounty on the al-Qaeda leader's head.

Her version, based on evidence from sources in what she calls the "intelligence community", contradicts the official account that bin Laden was tracked down through surveillance of his trusted courier.

Pakistani officials have always denied that bin Laden was sheltered in the country, or that Islamabad had any prior knowledge of the secret mission in which he was killed.

But Dr Hillhouse, who is known for her links to private military contractors that work extensively with the CIA, said that Pakistan gave permission for a covert mission which would then be covered up by a claim that bin Laden had been killed in a drone strike.

"The [Inter-Services Intelligence] officer came forward to claim the substantial reward and to broker US citizenship for his family," she writes on her intelligence blog, The Spy Who Billed Me.

"My sources tell me that the informant claimed that the Saudis were paying off the Pakistani military and intelligence (ISI) to essentially shelter and keep bin Laden under house arrest in Abbottabad, a city with such a high concentration of military that I'm told there's no equivalent in the US."

After confirming bin Laden's presence in the military town, the US approached Pakistan's military leaders securing their co-operation in return for cash and a chance to avoid public humiliation, according to Dr Hillhouse's account.

The theory, if true, may explain how American black hawk helicopters were then able to fly deep into Pakistan territory in May without encountering resistance. The plan may then have unravelled when one of the helicopters crash-landed, blowing the cover story.

According to the account leaked to the American media, planning for the raid was rooted in the discovery in August 2010 of Abu Ahmed al-Kuwaiti, bin Laden's courier. The CIA began tracking his car, and he was supposedly watched driving into the Abbottabad compound.

The CIA was then said to have placed the compound under surveillance and discovered that in addition to al-Kuwaiti and his brother, another man lived there but never left except to pace around the compound yard. Agents became convinced this man was bin Laden.

The US is said to have tried various schemes to confirm that "the pacer" was the world's most wanted man, including the launch of a bogus immunisation drive in the area. It was reportedly hoped that bin Laden's children would come forward and be identified by their DNA.

However, over the past three months there has been a consistent stream of speculation that the US account is too neat and may have been forcefully leaked in order to protect a crucial human intelligence source – possibly an al-Qaeda defector – who disclosed the vital information.

"The co-operation was why there were no troops in Abbottabad," wrote Dr Hillhouse. "It had always seemed very far-fetched to me that a helicopter could crash and later be destroyed in an area with such high military concentration without the Pakistanis noticing."

But in the immediate aftermath of the raid, some residents of Abbottabad, where bin Laden had lived for five years, claimed that they had received mysterious visits a night earlier, warning them to stay inside with their lights off.

A senior Pakistani security official denied that the ISI had sheltered bin Laden. "We don't use toilet paper – we wash," he said. "But toilet paper is all this theory is good for."

A spokesman for the State Department's bureau of diplomatic security, which oversees the reward programme, said: "We do not comment on rewards. People's lives are at stake and we must ensure the security of our sources."

He added, however, that the White House had said no reward would be paid following the death of bin Laden, and that under the law governing them, they could not be paid to US and foreign government employees.